稻虱缨小蜂对吡虫啉处理的水稻植株挥发物的行为反应

Behaviour response of Anagrus nilaparvatae (Pang et Wang) to rice plants treated with imidacloprid

利用"Y"型嗅觉仪测定稻虱缨小蜂对吡虫啉处理的水稻植株挥发物的行为反应,并通过GC-MS对挥发物组分进行了定性和定量分析。行为测试结果表明:吡虫啉和施用了吡虫啉的不同水稻品种挥发物对稻虱缨小蜂的寄主选择行为无明显影响。稻虱缨小蜂在不同浓度吡虫啉处理的水稻植株之间表现出明显的嗅觉偏好。当褐飞虱密度为10头/苗时,与高浓度吡虫啉处理相比,低浓度吡虫啉处理植株释放的挥发物引诱到了更多的稻虱缨小蜂(施药5天除外)。GC-MS分析发现:与对照植株释放的挥发物相比,吡虫啉处理的稻株挥发物组分种类不变;吡虫啉浓度不同导致水杨酸甲酯等8种组分的相对含量明显不同;同时一些组分的相对含量因吡虫啉浓度与水稻品种、褐飞虱密度及施药天数等因子的互作发生了明显改变。

Orientation responses of Anagrus nilaparvatae to rice plants treated with imidacloprid were studied using Y-tube olfactometer. The results indicated that imidacloprid, or different rice varieties treated with imidacloprid had no effect on the orientation behaviour of A. nilaparvatae. A. nilaparvatae exhibited much preference to volatiles emitted from rice plants treated with imidacloprid. When the density of N. lugens was 10 females per plant, a majority of the wasps were attracted to volatiles released from rice plants treated with low concentration of imidacloprid, but not to high concentration treatment. Then, 40 components were collected from headspace of rice plants treated with imidacloprid with solid phase microextractrion （SPME）, 14 of which were identified by gas chromatography coupled with mass spectrometry （GC-MS）. Imidacloprid treatments did not result in the emission of new compounds, but rather the proportions （% of total peak area） among the compounds in the blend were altered. The proportions of 8 components had significant differences in 3 levels of imidacloprid concentration treatments. Furthermore, the proportions of some components were significantly changed due to interactions between concentrations of imidacloprid and rice varieties, densities of N. lugens, days after treatments.